This invention generally pertains to dispenser valves. More specifically, the invention relates to a self-closing dispenser valve or tap useful for dispensing various flowable products.
The invention is particularly applicable to dispensing valves for throwaway containers, such as "bag-in-the-box" or "membrane" type containers, and will be described with particular reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader applications and may also be adapted to use in many other environments where the availability of a simple, low cost dispensing valve would be desirable.
Bag-in-the-box or membrane packaging of a variety of commodities is becoming increasingly popular due to its economy, convenience, and storage capabilities. Such packaging is entirely disposable and typically includes a flexible plastic bag which receives a flowable product in a sterile environment. A paperboard box is typically used for enclosing the filled bag to facilitate safe transportation and handling. Examples of commodities economically packaging in this manner include free-flowing fluids such as milk, juice and wine, and viscous products, such as ketchup, cooking oil and detergents. The packaging is generally available in a variety of sizes, eg., 1, 3, 5 and/or 10 gallons.
A valve or tap is provided on the container to facilitate controlled dispensing of the container contents. One conventional valve includes a flexible walled tube having an opening at the base area thereof which communicates with the interior of the container. The flexible tube defines a sealing surface and is received in an outlet housing disposed generally at right angles to the axis of the container opening. An axially projecting toggle allows the user to distort the flexible tube, i.e., the sealing surface, and form a liquid flow passage from the container to the outlet housing. When the toggle is not deflected, the walls of the flexible tube are urged into covering relation with the outlet housing to prevent the flow of liquid. The toggle is formed integrally with the flexible tube itself.
Such prior art type valves, however, suffer from several disadvantages, the major one being their cost. Conventional valves for disposable packaging are fairly expensive, although it is desired that they be as low cost as possible. Moreover, most prior valves of this general type also experience problems with sealing effectiveness and pressure capacity. That is, most prior art valves use little more than a line contact to seal the product in the container. Therefore, if any nicks or deformities occur during manufacture of the valve and/or the bag, unacceptable leakage will oftentimes occur. Any effort to overcome these problems involves a significant increase in the amount of material used in constructing the valve and a corresponding increase in the valve cost.
Accordingly, it has been considered desirable to develop a new and improved valve or tap which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.